Method and apparatus for fabricating a roof on large concrete structures



Dec. 1,5, 1964 J. J. WATSON 3,161,703

METHOD AND APPARATUS FOR FABRICATING A Rooi;1

ON LARGE CONCRETE STRUCTURES Filed Feb. 19, 1962 s sheets-shed 1 JAMES JWasolv ATTORNEYS Dec. 15, 1964 .1. J. wA-'rsoN 3,161,703

METHOD AND APPARATUS FOR FABRICATING A RooF 0N LARGE CC)I\CRE'1`ESTRUCTURES 3 Sheets-Sheet 2 Filed Feb. 19, 1962 INVENTOR. JAMES J.Marsan BY n TTQ/fyg Dec. 15, 1964 J. J. wATs N 3,161,703

METHOD AND APPARATUS RoR EABRICATTNG A RooE oN LARGE CONCRETE STRUCTURESFiled Feb. 19, 1962 3 Sheets-Sheet 3 34 I 36 5&9 50 33 30 m 37 35 42 2'`j Y WM 44 INVENTCR. JAMES J. WATSON TTOPIVEVS United States Patent O,

3,161,7@3 METHD AND AKPARATUS FR FABRECATHNG A RQCDF N LARGE CQNCREEESTRUCTURES laines 5. Watson, 4331 Ridgeway Drive, Kansas Qity, Mo. FiledFeb. 19, 1962, Ser. No. 174,229 6 Claims. (Cl. 264-32) This inventionrelates to supports for forms used in pouring massive concretestructures, and more particularly to improvements in the method andapparatus for supporting roof forms for pouring concrete roofs inplaceon very large column free limited interior access constructions.

Heretofore, the method and apparatus used for supporting under or softforms for pouring in-place massive concrete roof slabs usually requireda huge complex of both Vertical and horizontal framing members reachingfrom the iloor of the construction up to the concrete forms for the roofand necessitated the time-consuming and expensive procedure ofprogressive cribbing during which shoring members were tied, cross-tiedand braced. In assembling such form-supporting structures, each memberwas assembled individually and generally no fixed combination of memberscould be employed to accelerate the erection since each job required adifferent elevation at the top `in order to obtain the particulardimensional requirements of the subsequently poured concrete roof. Afterthe concrete was poured, and obtained selfsupporting strength, eachmember was disassembled individually and often a great deal of time wasrequired for removal due to limited access to the inside of the concreteconstruction. It is apparent that the method and apparatus heretoforeused for supporting roof forms in large column free limited accessconstructions was difficult and time-consuming and added materially tothe cost thereof.

The principal objects of the present invention are: to provide a methodfor erecting concrete roof soiit form supports in large tank-likeconstructions which is substantially less expensive and lesstime-consuming than heretofore; to provide a removable apparatus forsupporting such forms which is simpler in construction and requiresconsiderably fewer parts than heretofore; to provide such a method andapparatus wherein a working deck is maintained between theform-supporting structure and 'he tank bottom to carry workmen andmaterials in a convenient position for simplifying the support structureassembly; to provide such a method and apparatus wherein a plurality ofcircumferentially spaced pockets are formed in the construction wall tosupply convenient support surfaces not requiring vertical shoring; toprovide such a method and apparatus which take advantage of expandabletelescopic beams for ease of assembly and disassembly within theconstruction interior; to provide such a method and support structurewhich require only a single easily removable self-stabilizing centralsupporting column having multiple sections for vertical sharing withinthe tank construction; to provide such a supporting column having aradial flange at the elevation 0f support surfaces formed in the tankwall whereby horizontal longitudinally telescopic beams may be supportedat each end thereof; to provide such a supporting column having acircular platform on the top thereof forming an upper bearing ringextending above the tank wall upper edge a distance approximating theheight of a frusto-conical roof to be formed, said upper bearing ringbeing adapted to support the inner ends of radially extendinglongitudinally telescopic beams supported at the other ends thereof inwall pockets, said beams forming a frustoconical frame structure adaptedto supportV a concretereceiving soirlt form deck; and to provide such amethod 3,l 5 L7M Patented Dec. l5, 15%64 ice and temporary structurewhich offers extreme simplicity in dismantling and removal through aconventional central roof opening.

Gther objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings wherein are set forth by way of illustration and examplecertain ernbodiments of this invention.

FIG. l is a` cross-sectional view in elevation through a concrete sewagetreating digester showing the roof softit form supporting structure inplace immediately prior to the dismantling and remo-val thereof, therear upper telescopic beams thereof not being shown for clarity ofillustration.

FlG. 2 is a fragmentary perspective view of the digester of FlG. 1 witha portion of the roof broken away to show details of the roof soiiitform supporting structure and working deck.

FIG. 3 is a fragmentary perspective sectional view through the centralsupporting column on an enlarged scale, particularly showing the lowerand upper beam bearing rings.

FIG. 4 is a fragmentary sectional View on an enlarged scale particularlyshowing the pockets in the digester wall for receiving and supportingthe telescopic beams.

FIG. 5 is a cross-sectional view through a telescopic beam on anenlarged scale showing the locking structure for selectively locking thebeams in teiescoped condition.

Referring to the drawings in more detail:

The reference numeral l generally indicates a structure known as asewage digester which is herein illustrated as an example of one type ofconstruction particularly adapted to benefit from this invention. Thedigester 1 is essentially a large partially underground tank havingoverall outside dimensions in the order of SO-feet in height and SO-feetin diameter. The digester 1 is characterized as being entirely ofreinforced concrete 2 and, in the illustrated example, has an invertedregular frustoconical floor 3 terminating at the lowermost portionthereof in a small circular platform 4. A wall 5 extends verticallyupwardly from the upper terminus 6 of the floor 3 and has an upperhorizontal circular edge 7 and a cylindrical inside surface S. Acircular vertically extending groove 9 is provided in the upper edge 7between the inside surface 8 and the wall outside surface 1t) to helpform an effective anchor and seal between the edge 7 and the roof 11 nowto be described.

The roof 11 is a regularfrusto-conical reinforced concrete member which,after construction, is supported entirely on the wall edge 7 and has arelatively small central opening 12 therethrough, The outer rim orperipheral portion 13 of the roof 11 is generally thicker than thebalance of the roof to support the increased shear loads produced as theperiphery of the cone is approached. The central opening 12 in the roof11 is surrounded by a cylindrical integral concrete ring 14.

It is to beiunderstood that the door 3, wall 5 and roof 11 are formed byany one of several conventional methods and structures, and such methodsand structures will, therefore, not be referred tto in detail herein.One variation, however, in the conventional design and construction ofthe wall 5 in practicing the present invention is that an upper group ofpockets 15 and a lower group of pockets 16 are formed in horizontallycircumferentially spaced relation about the cylindrical inside surface 8and extend radially outwardly into the wall 5. The upper group ofpockets 15 and lower group of pockets 16 respectively form an uppergroup of ledges 17 and a lower group of ledges 18. The upper ledges 17are adjacent the wall upper edge 7 and the lower group of ledges 18 arespaced atentos El downwardly from the upper ledges i7, as bestillustrated in FIG. 4.

A removable self-stabilizing multiple section supporting column 19 iserected on the platform i of the dige-ster 1 and, in the illustratedexample, when completed come prises a lower column section 2d, anintermediate column section 21 and an upper column section 22. The lowercolumn section 2d terminates at the lower end thereof in a radiallyextending circular flange 23 which rests on the platform 4 and providesindependent vertical stabilization for the supporting column 19. It isdesirable that a layer of grout 24 be placed between the flange 23 andthe platform 4 to aid in adjusting the plumbness of the lower columnsection 2t? and, after the grout has hardened, maintaining same inplumb. The lower column section 20 is positioned to extend axially ofthe cylindrical inside surface 8.

A collar 25 is assembled on the upper end of the lower column sectionZtl, preferably prior to locating the section 2d on the platform 4. Thecollar 25 is provided with a plurality of gussets 26 preferably weldedin place to add rigidity thereto and is adapted to receive a pluralityof bolts 27 for securing thereagainst a flange 28 fixed to the lower endof the intermediate column section 2l.

When assembled, the intermediate column section 21 extends axially withand above the lower column section Z and :the lower and intermediatesections 2t) and 2l 1re free standing without additional support due tothe plumbness thereof and the stabilizing effect of the flange Z3.

A collar 30 is assembled on the upper end of the intermediate columnsection Z1 preferably prior to the coniection of the section 2 with thelower column section Ztl. The collar 3i) is rigidly supported on theintermediate column section 2l by means of gussets 3l preferably weldedrespectively thereto and contains a plurality of :ircumferentiallyspaced vertically extending bores 32 adapted to receive bolts 33extending through a flange 34 rigidly connected to the lower end of theupper column ;ection 22.

Preferably prior to the assembly of the upper column section 22 with thesection 2l, a plurality of longitudinally :elescopic lower spanningshores or beams 35 are expanded and supported in the digester i ashereinafter described. l`he collar 30 has a diameter substantiallygreater than yhe flange 34 producing a horizontally extending lower)caring ring 36 which is positioned at the elevation of ,he lower groupof ledges 18 as best illustrated in FIG. l. The beams 35 are insertedinto the digester interior ',hrough the open top (in absence of the roofll) and ex- )anded in systematic opposition into supported Contact at heinner ends 37 thereof and outer ends 38 thereof re- ;pectively on fthelower bearing ring 36 and lower ledges i3. The beams are preferablyplaced in regular circumerentially spaced radial relation about theintermediate :olumn section 2li. The inner ends 37 and outer ends 38 3fthe beams 35 respectively have lip portions 39 which Jrovide areas ofcontact with lthe bearing ring 36 and :he lower ledges l.

The beams 35 may be of any suitable longitudinally expandable type,however, inthe illustrated example, each :omprises two telescoping endmembers il@ and 41 of -elatively light weight plate steel and a latticecentral nember 42 adapted to slidably receive the members iii and 41 ateach end thereof. Eyebolts 43 adjacent each 2nd of the lattice member 42and operably connected vith friction plates 44 permit longitudinallyslidable adustment of the members 44B and di with respect to the atticemember 42 to change the overall length of the :earn 35 and also providesa suitable lock between the nembers when the desired length is obtained.When he beams 53 are expanded into the desired positions, the ipportions 39 on the inner ends 37 are preferably spot velded to the lowerbearing ring 36 at 45 and grout lo s placed in the lower pockets 16adjacent the lip portions 39 at the outer ends 38 to temporarilystabilize the respective beams 35 and prevent a possible shifting out oftheir desired positions. Prior to the stabilizing of the respectivebeams 35, it is desirable that the plumbness of the lower andintermediate column sections Ztl and 2l be checked to insure the propersubsequent centering of the concrete soft molds or forms more fullydescribed hereinafter.

A plurality of planks 47 are laid over and between the lower beams 35 toform a plank decking or working deck d adapted to conveniently supportworkmen, tools and material (all not shown) for completing theconstruction.

The upper column section 22 is assembled with the intermediate columnsection 2l preferably after the working deck i8 is installed. rEhesection 22 is provided with a circular platform 49 on the top thereofgreater in diameter than the flange 23, collar 25 and collar 3i) andforming an upper bearing ring 5d extending above the wall upper edge 7 adistance approximating the height of the frusto-conical roof lll. Aplurality of vertically extending gusset plates 5l are secured to theupper column section 22 preferably by welding and extend radiallyoutwardly thereof in circumferentially spaced relation forming accesspassageways 52 with the open interior 53 of the upper bearing ring 5d.The passageways 52 extend into the interior of the digester 1 from theoutside thereof. The upper bearing ring 5t) has a peripheral downwardlyextending outer lip 54 welded thereto for additional rigidity and also aplurality of circumferentially spaced radial plates 55 adapted yto besecured to the respective gusset plates 5l, in the illustrated exampleby bolts 56. A suitable bearing block, in the illustrated example awooden ring 57, has inside and outside diameter dimensions whereby it isadapted to rest on the upper bearing fing 50 without overlap on theperiphery thereof or obstruction of the access pasasgeways 52. The ring57 has the upper edge 58 thereof sloping conically downwardly andoutwardly at approximately the same angle as the roof 11 to be formed.

A plurality of bearing blocks 59 are inserted into the upper group ofpockets 15 and rest upon the upper ledges 17 thereof. The blocks 59preferably have the upper edge or surface 6i) thereof sloping downwardlyand outwardly of the diges'ter l at an angle which approximates theintended slope of the roof lll.

A plurality of longitudinally telescopic upper spanning shores or beams6i similar to lthe beams 35 are inserted into the open top of thedigester 1 and temporarily expanded into supported contact at the innerends 62 and outer ends 63 respectively thereof on the wooden ring 57 andbearing blocks 59. As indicated in FIG. 2, when the upper beams 6l arelocked into position, a frusto-conical frame structure 64' is quicklyand easily produced. A plurality of supporting cross members 65 are thenlaid transversely of the respective upper beams dl and a soiiit formdeck 66 is secured thereover in the conventional manner for producingthe mold which will subsequently form :the under side of the roof il.Central opening forms 67 adapted to produce a conventional centralopening of greater diameter 'than the upper bearing ring 50 are securedto the form deck do in the usual manner and suitably braced withsupports 68 for maintaining the central opening forms in fixed positionwith respect to the form deck when-'the concrete is subsequently pouredtherearound. The roof outer surface forms and supports therefor (notshown) are completed in a conventional manner and the entire roof 11 maybe poured as a unit or in sections as desired. Y

After the concrete in the roof 1l has reached selfsupporting strength,the dismantling of the above-described form supporting structure mayproceed. ingress and egress of men, tools and materials are convenientlymaintained through the open access passageways 52. Al-

though several different sequences of steps may be used in thedismantling procedure, it is generally desirable to first collapse theupper beams 61, laying same on the Working deck 48, and coincidentallytherewith removing the cross members 65 and form deck 66. After removalof the central opening forms 67, the upper column section 22 may beunbolted from the intermediate column section 21 and removed axiallyupwardly from the digester 1 through the central opening 12. The centralopening 12 then provides a convenient passageway for the removal of theupper beams 61 and form deck parts resting on the working deck 48. Theprogressive dismantling and removal of the working deck, lower beams 35and the remaining sections of the supporting column 19 may then beaccomplished quickly without the need for complex procedures.

It is to be understood that the invention above-described does away withthe need for the expensive, timeconsuming, cumbersome, complex ofvertical shoring heretofore required for similar construction jobs, andin its place provides a simple, fast and eicient structure and methodwhich results in considerable time and labor savings. An importantfeature of this invention is the use of the previously formed wall orwalls of the structure for carrying the roof loading at the time ofpouring, thereby utilizing said walls to an immediate advantage for afunction which they ultimately have to assume anyway, since inpractically all building structures the walls carry at least part of theroof load and with construction similar to the illustrated example, allof the roof load. The invention is well adaptable to other shaped roofssuch as flat or inverted cone constructions. The working deck may beinstalled at any convenient level and nds additional utility, forexample, in the undercoating of the roof after the forms are removed.

It is to be further understood that While one example of this inventionhas been illustrated and described, it is not to be limited to thespecific form, method or arrangement of parts herein described and shownexcept insofar as such limitations are included in the claims.

What I claim and desire to secure by Letters Patent is:

1. The method of supporting a roof soit form deck while fabricatinglarge structures of the type in the order of about 50 feet in width andhaving a floor and a concrete roof and a wall with an upper edge and aninside surface, said method comprising the steps of:

(a) providing a group of circumferentially spaced members on said walland having ledges adjacent said wall inside surface and near said wallupper edge,

(b) erecting in sections a temporary supporting rigid column in uprightrelation on said iioor at the vertical center of the structure with aspread of engagement of the column with the floor that the column isself-stabilizing,

(c) assembling bearing means on said column forming a supporting surfaceextending around and outwardly of said column at an elevationapproximating the height of at least a portion of said roof,

(d) temporarily expanding a plurality of longitudinally telescopic beamsinto supported contact at opposite ends thereof respectively on saidbearing means supporting surface and said ledges, said beams being rigidand circumferentially spaced and extending radially from the column andproducing a form supporting frame structure, and

(e) laying the form deck on said frame structure, whereby the entirevertical support for said form deck is provided by said column and wallthrough said beams.

2. The method of supporting a roof sotiit form deck while fabricatinglarge structures of the type in the order of about feet in width andhaving a oor and an at least partially surrounding wall with an upperhorizontal edge and an inside surface and a generally frusto-conicalconcrete roof supported entirely on said edge and having a centralopening therethrough, said method comprising the steps of:

(a) forming a group of circumferentially spaced integral members in saidwall having ledges adjacent said wall inside surface and near said wallupper edge,

(b) positioning a lower section of a temporary multiple section rigidsupporting column in upright relation on said tloor substantially at thevertical center of said structure with a spread of engagement of a baseon said lower section with the oor that the column is self-stabilizing,

(c) moving additional column sections onto said lower column section andsecuring them in end to end alignment,

(d) temporarily assemblingV an upper column section axially of saidlower column section and provided with a platform of greater diameterthan said column forming a bearing ring surface above said wall upperedge a distance approximating the height of said roof,

(e) temporarily expanding a plurality of longitudinally telescopic beamsinto supported contact at opposite ends thereof respectively on saidbearing ring surface and said ledges with said beams being rigid andcircumferentially spaced and extending radially from `said bearing ringproducing a frusto-conical form supporting frame structure, and

(f) laying the form deck including a central opening form of greaterdiameter than said bearing ring on said frame structure, whereby theentire vertical support for said form deck is provided by said columnand wall through said beams and said column and beams are removablethrough said central opening.

3. The method of constructing the support for a roof soit form deckduring the fabricating of large structures of the type in the order ofabout 50 feet in width and having a floor and a concrete roof and a wallwith an upper edge and an inside surface, said method comprising thesteps of:

(a) forming ladjacent said inside surface an upper group of.circumferentially spaced pockets having ledges located at a leveladjacent said wall upper edge and a lower group of spaced pockets havingledges located at a level downwardly from said upper ledges,

(b) erecting a temporary self-stabilizing rigid supportting column inupright relation on said oor,

(c) positioning said column substantially at the vertical center of saidstructure,

(d) assembling lower bearing means on said column at the level of saidlower ledges forming a supporting surface around and outwardly of saidcolumn,

l (e) temporarily expanding a plurality of longitudinally telescopiclower beams into supported contact at opposite ends thereof respectivelyon said lower bearing means supporting surface and on said lower ledgesin circumferentiallyspaced relation about said column, said beams beingrigid and extending radially of the column producing a deck supportingstructure,

(f) laying a working deck on said lower beams,

(g) assembling upper bearing means with said column at an elevationapproximating the height of at least a portion of said roof,

(h) temporarily expandinga plurality of longitudinally telescopic upperbeams into supported contact at opposite ends thereof respectively onsaid upper bearing means and said upper ledges with said upper beamsbeing rigid and circumferentially spaced and extending radially fromsaid bearing means producducing a form supporting frame structure, and

(i) laying the form deck on said frame structure, whereby the entirevertical support for said working deck and form deck is provided by saidcolumn and wall through said upper beams.

4. The method of fabricating large concrete tank structures of the typein order of about 50 feet in width and having a floor and a verticallyextending wall with an upper horizontal circular edge and a cylindricalinside surface and a regular frusto-conical roof supported entirely onsaid edge and having a central opening therethrough, said methodcomprising the steps of:

(a) forming said floor,

(b) forming said wall in contact with said iioor and with an upper and alower group of circumferentially spaced pockets horizontally extendingradially outwardly from said cylindrical inside `surface into said wallsand respectively presenting an upper group of spaced ledges at a leveladjacent said wall upper edge and a lower group of spaced ledges locatedat a level downwardly from said upper ledges,

(c) erecting a lower section of a temporary multiple section rigidsupporting column in upright relation on said oor with a spread ofengagement of the column with the door that the column isself-stabilizlng:

(d) positioning said lower column section axially of said cylindricalinside surface,

(e) assembling a collar on said column provided with a horizontallyextending radial flange at the level n of said lower ledges forming alower bearing ring,

() temporarily expanding in systematic opposition a plurality oflongitudinally telescopic lower beams into supported Contact at oppositeends thereof respectively on said lower bearing ring and on said lowerledges in regular circumferentially spaced radial relation about saidintermediate column section, said lower beams being rigid,

(g) temporarily securing said lower beams at points of supported contacton said lower bearing ring and said lower ledges,

(h) laying .a working deck on said lower beams,

(i) assembling an' upper column section with said column and providedwith a circular platform on the top thereof greater in diameter thansaid column and forming an upper bearing ring extending above said wallupper edge a distance approximating the height of said roof,

(j) temporarily expanding a plurality of longitudinally telescopic upperbeams into supported contact at opposite ends Vthereof respectively onsaid upper bearing ring and said upper ledges, said upper beams beingrigid and circumferentially spaced and extending radially from saidbearing ring producing a frustoconical frame structure, v f

(k) laying a softit form deck including a central opening form ofgreater diameter than said upper bearing ring on said frame structure,

(I) pouring concrete over said form deck forming said roof, f

(m) permitting said concrete to reach self-supporting strength,

(n) dismantling said frame structure and form deck and upper columnsection between said roof and said working deck,

(o) removing said frame structure and form deck and upper column sectionfrom said tank through said central opening,

(p) dismantling said working deck and lower beams,

and

(q) removing said working deck and lower beams and balance of saidcolumn through said central opening.

5. A structure adapted to support a soilt form deck tor molding aconcrete frusto-conical roof on a large con- :rete tank in the nature of50 feet in diameter and of the ype having a iioor and a verticallyextending wall having in upper horizontal circular edge and acylindrical inside surface, said frusto-conical roof after formationbeing iupported entirely on said edge and having a central openngtherethrough, said structure comprising:

(a) an upper andra lower group of circumferentially spaced pocketshorizontally extending radially outwardly of said cylindrical insidesurface into said walls and respectively presenting an upper group ofledges at a level adjacent said wall upper edge and a lower group ofledges at a level spaced downwardly from said upper ledges,

(b) a removable self-stabilizing multiple section supporting columnhaving a rigid lower section positioned in upright relation on saidfloor axially of said cylindrical inside surface,

(c) an intermediate rigid column section assembled axially with andextending above said lower column section,

(d) a collar on said intermediate column section provided with ahorizontally extending radial flange at the level of said lower ledgeand forming a lower bearing ring,

(e) a plurality of longitudinally telescopic lower rigid beams supportedand temporarily secured at opposite ends thereof respectively on saidlower bearing ring and on said lower ledges in regular circumferentiallyspaced radial relation about said intermediate column section,

(j) a working deck resting on said lower beams,

(g) an upper rigid column section assembled axially with saidintermediate column section and provided with a circular platform on thetop thereof greater in diameter than said column and forming an upperbearing ring extending above said wall upper edge a distanceapproximating the height of said roof,

(h) a plurality of longitudinally telescopic upper rigid beams supportedat opposite ends thereof respectively on said upper bearing ring andsaid upper ledges in regular circumferentially spaced radial relationproducing a truste-conical frame structure,

(i) said frame :structure being adapted to support said form deckincluding a central opening form of greater diameter than said upperbearing ring,

(j) whereby said frame structure and form deck and upper column sectionmay be dismantled and removed through said central opening prior to thedismantling -and removal through said opening of said working deck andlower beams and intermediate and lower column sections.

6. A structure adapted to support a soflit form deck for molding aconcrete frusto-conical roof on a large concrete tank of the type havinga floor and a vertically extending wall having an upper horizontalcircular edge and a cylindrical inside surface, said frusto-conical roofafter formation being supported entirely on said edge and having acentral opening therethrough, said structure comprising:

(a) a group of circumferentially spaced pockets horizontally extendingradially outwardly of said cylindrical inside surface into said wallsand respectively presenting a group of ledges at a level adjacent saidwall upper edge,

(b) a removable self-stabilizing multiple section supporting columnhaving a rigid lower section positioned in upright relation on saidiioor axially of said cylindrical inside surface,

(c) an upper rigid column section assembled axially with said lowercolumn section and provided with a circular platform on the top thereofgreater in diameter than said column and forming an upper bearing ringextending above said wall upper edge a distance approximating the heightof said roof,

(d) a plurality of longitudinally telescopic upper rigid beams supportedat opposite ends thereof respectively on said supper bearing ring andsaid ledges in regular circumferentially spaced radial relationproducing a frusto-conical frame structure,

(e) said frame structure being adapted to support said form deckincluding a central opening form of great- 975,525 er diameter than saidupper bearing ring, 1,016,485 (f) whereby said frame structure and formdeck and 1,584,658 column may be dismantled and removed through said1,891,160 central opening. 5 2,7 05,359 2,901,809 References Cited bythe Examiner 3,072,996

UNITED STATES PATENTS 1@ Harshbarger 25-124 Elsmere 25--124 Rutten25-124 Iespersen 264-32 Strandberg 264-32 Ciesla 25-124 McGuire 25--1315ALEXANDER H. BRODMERKEL, Primary Examiner.

4 10 MICHAEL V. BRINDISI, ALEXANDER H. BROD- MERKEL, Examiners.

2. THE METHOD OF SUPPORTING A ROOF SOFFIT FORM DECK WHILE FABRICATINGLARGE STRUCTURES OF THE TYPE IN THE ORDER OF ABOUT 50 FEET IN WIDTH ANDHAVING A FLOOR AND AN AT LEAST PARTIALLY SURROUNDING WALL WITH AN UPPERHORIZONTAL EDGE AND AN INSIDE SURFACE AND A GENERALLY FRUSTO-CONICALCONCRETE ROOF SUPPORTED ENTIRELY ON SAID EDGE AND HAVING A CENTRALOPENING THERETHROUGH, SAID METHOD COMPRISING THE STEPS OF: (A) FORMING AGROUP OF CIRCUMFERENTIALLY SPACED INTEGRAL MEMBERS IN SAID WALL HAVINGLEDGES ADJACENT SAID WALL INSIDE SURFACE AND NEAR SAID WALL UPPER EDGE,(B) POSITIONING A LOWER SECTION OF A TEMPORARY MULTIPLE SECTION RIGIDSUPPORTING COLUMNS IN UPRIGHT RELATION ON SAID FLOOR SUBSTANTIALLY ATTHE VERTICAL CENTER OF SAID STRUCTURE WITH A SPREAD OF ENGAGEMENT OF ABASE ON SAID LOWER SECTION WITH THE FLOOR THAT THE COLUMN INSELF-STABILIZING, (C) MOVING ADDITIONAL COLUMN SECTIONS ONTO SAID LOWERCOLUMN SECTION AND SECURING THEM IN END T END ALIGNMENT, (D) TEMPORARILYASSEMBLING AN UPPER COLUMN SECTION AXIALLY OF SAID LOWER COLUMN SECTIONAND PROVIDED WITH A PLATFORM OF GREATER DIAMETER THAN SAID COLUMNFORMING A BEARING RING SURFACE ABOVE SAID WALL UPPER EDGE A DISTANCEAPPROXIMATING THE HEIGHT OF SAID ROOF, (E) TEMPORARILY EXPANDING APLURALITY OF LINGITUDINALLY TELESCOPIC BEAMS INTO SUPPORTED CONTACTED ATOPPOSITE ENDS THEREOF RESPECTIVELY ON SAID BEARING RING SURFACE AND SAIDLEDGES WITH SAID BEAMS BEING RIGID AND CIRCUMFERENTIALLY SPACED ANDEXTENDING RADIALLY FROM SAID BEARING RING PRODUCING A FRUSTO-CONICALFORM SUPPORTING FRAME STRUCTURE, AND (F) LAYING THE FORM DECK INCLUDINGA CENTRAL OPENING FROM OF GREATER DIAMETER THAN SAID BEARING RING ONSAID FRAME STRUCTURE, WHEREBY THE ENTIRE VERTICAL SUPPORT FOR SAID FORMDECK IS PROVIDED BY SAID COLUMN AND WALL THROUGH SAID BEAMS AND SAIDCOLUMN AND BEAMS ARE REMOVABLE THROUGH SAID CENTRAL OPENING.
 6. ASTRUCTURE ADAPTED TO SUPPORT A SOFFIT FORM DECK FOR MOLDING A CONCRETEFRUSTO-CONICAL ROOF ON A LARGE CONCRETE TANK OF THE TYPE HAVING A FLOORAND A VERTICALLY EXTENDING WALL HAVING AN UPPER HORIZONTAL CIRCULAR EDGEAND A CYLINDRICAL INSIDE SURFACE, SAID FRUSTO-CONICAL ROOF AFTERFORMATION BEING SUPPORTED ENTIRELY ON SAID EDGE AND HAVING A CENTRALOPENING THERETHROUGH, SAID STRUCTURE COMPRISING: (A) A GROUP OFCIRCUMFERENTIALLY SPACED POCKETS HORIZONTALLY EXTENDING RADIALLYOUTWARDLY OF SAID CYLINDRICAL INSIDE SURFACE INTO SAID WALLS ANDRESPECTIVELY PRESENTING A GROUP OF LEDGES AT A LEVEL ADJACENT SAID WALLUPPER EDGE, (B) A REMOVABLE SELF-STABILIZING MULTIPLE SECTION SUPPORTINGCOLUMN HAVING A RIGID LOWER SECTION POSITIONED IN UPRIGHT RELATION ONSAID FLOOR AXIALLY OF SAID CYLINDRICAL INSIDE SURFACE, (C) AN UPPERRIGID COLUMN SECTION ASSEMBLED AXIALLY WITH SAID LOWER COLUMN SECTIONAND PROVIDED WITH A CIRCULAR PLATFORM ON THE TOP THEREOF GREATER INDIAMETER THAN SAID COLUMN AND FORMING AN UPPER BEARING RING EXTENDINGABOVE SAID WALL UPPER EDGE A DISTANCE APPROXIMATING THE HEIGHT OF SAIDROOF, (D) A PLURALITY OF LONGITUDINALLY TELESCOPIC UPPER RIGID BEAMSSUPPORTED AT OPPOSITE ENDS THEREOF RESPECTIVELY ON SAID SUPPER BEARINGRING AND SAID LEDGES IN REGULAR CIRCUMFERENTIALLY SPACED RADIAL RELATIONPRODUCING A FRUSTO-CONICAL FRAME STRUCTURE, (E) SAID FRAME STRUCTUREBEING ADAPTED TO SUPPORT SAID FORM DECK INCLUDING A CENTRAL OPENING FORMOF GREATER DIAMETER THAN SAID UPPER BEARING RING, (F) WHEREBY SAID FRAMESTRUCTURE AND FORM DECK AND COLUMN MAY BE DISMANTLED AND REMOVED THROUGHSAID CENTRAL OPENING.